In a wireless communication system, wireless signals are affected by propagation environments, thereby producing reflection, diffraction and scatter in propagation paths. Hence, when signals of a transmitter end arrive at a receiver end, the signals are not transmitted by a single path, but are superimposition of multiple signals transmitted by multiple paths, and this phenomenon is called as a multipath effect. As actual distances of the propagation paths are different, times of arrival of the signals of the paths at the receiver end are different. In an actual communication system, it is often needed to estimate time delay of the multiple paths. Accurate estimation of the time delay of the multiple paths may improve accuracy of measurement of wireless channels, thereby improving channel transmission performance, and furthermore, may also improve positioning precision in positioning applications.
Currently, an existing multipath time delay estimation method often adopts a multiple signal classification (MUSIC) algorithm with super-resolution, including a frequency domain MUSIC algorithm and a time domain MUSIC algorithm. FIG. 1 is a flowchart of an existing method for estimating multipath time delay based on the frequency domain MUSIC algorithm. As shown in FIG. 1, the method includes: step 101: transmitting signals; step 102: receiving signals passing through wireless channels; step 103: performing channel estimation in the frequency domain; step 104: generating a covariance matrix by using the frequency domain MUSIC algorithm, and performing feature value decomposition and spectral peak search; and step 105: performing multipath time delay estimation.
FIG. 2 is a flowchart of an existing method for estimating multipath time delay based on the time domain MUSIC algorithm. As shown in FIG. 2, the method includes: step 201: transmitting signals; step 202: receiving signals passing through wireless channels; step 203: performing cross-correlation operations on transmission signals and received signals, so as to obtain cross-correlation values to which different time delays correspond; step 204: generating a covariance matrix by using the time domain MUSIC algorithm, and performing feature value decomposition and spectral peak search; and step 205: performing multipath time delay estimation.
It should be noted that the above description of the background is merely provided for clear and complete explanation of the present disclosure and for easy understanding by those skilled in the art. And it should not be understood that the above technical solution is known to those skilled in the art as it is described in the background of the present disclosure.